Machine tool grinding fixture

ABSTRACT

A fixture for refacing rectangular, cylindrical, or circular cutting tools with angled and curved surfaces including a radius device having a holder mounted for radial adjustment upon a rotary shaft and also having rotary adjustment in the plane of the shaft.

O Unlted States Patent 1151 3,653,163 Evon 5] Apr. 4, 1972 [s41 MACHINETOOL GRINDING FIXTURE 3,087,287 4/1963 Rombold ..51/225 3,039,244 6/1962Vickerman 51/216 UX [721 111mm Watemwn, 2,741,241 4/1956 Teather..125/11 06795 2,476,361 7/1949 Elliott ...51/225 [22] Filed: Mar.10,1970 1,873,224 8/1932 Shippy 51/216 X 3,187,737 6/1965 Oscar ..l25/1l21 Appl. No.: 18,105

Primary Examiner-Harold D. Whitehead 521 u.s.c1...s1/21sR,51/225,125/11A 51 Int. Cl ..B24b19/00 [57] ABSTRACT [58]Field ofSearch .151/2l6.6, 218,225; 125/1 1.7

A fixture for refacing rectangular, cylindrical, or circular [56]References Cited cutting tools with angled and curved surfaces includinga radius device having a holder mounted for radial adjustment UNITEDSTATES PATENTS upon a rotary shaft and also having rotary adjustment inthe plane of the shaft. 2,429,464 10/1947 Jearum ..125/l1 UX 2,771,72311/1956 Burleson ..5l/225 8Cla1ms,5DrawingF1gures INVENTOR. LOUIS J.EVON ATTORNEYS PATENTEDAPR 41972 SHEET 2 UP 3 MACHINE TOOL GRINDINGFIXTURE BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to machine tool grinding fixtures.

2. Description of the Prior Art Machine cutting tools take various formssuch as rectangular tools with angled surfaces or curved cutting edgesor cylindrical and circular cutting wheels which may have angled andcurved cutting teeth.

The difficulty of sharpening or refacing such tools is greatlycomplicated by the precise curvature or angles of the tools andtherefore it is desirable to have a tool fixture which can support thetool during the cutting process and position the tool so that it may bebrought in contact with a grinding wheel at any desired angle. It isfurther desirable that the fixture be capable of sweeping the toolacross a grinding wheel in a continuous motion so that a smooth cuttingsurface can be generated or reformed on the cutting portion of the tool.

Summary of the Invention The invention relates to a tool mountingfixture which permits a tool face to be ground with generally flat orcurved cutting edges at any desired angle on the tool.

The tool consists basically of a fixture in which a shaft is rotatablymounted and tool supporting structure is connected to one end of theshaft. The mounting structure comprises an arm extending radially fromthe shaft and a tool holding block that may be adjustably positioned atvarious radial stations on the arm. The holding block, in addition tothe radial adjustment, can also be tilted in a plane defined by the armand the rotatable shaft. The holding block includes various toolgripping attachments.

In one embodiment of the invention, the gripping attachment is avise-type clamp which can be adjustably positioned within the holdingblock. The vise clamp is particularly suitable for holding tools ofrectangular or oblong shape.

In another embodiment of the invention, tool gripping attachment isparticularly adapted to hold cylindrical or wheel type cutters. Theattachment includes a locking element which prevents the wheel fromrotating as individual teeth on the wheel are brought in contact withthe grinding wheel. This attachment is also capable of being adjustablypositioned within the tool holding block.

The angle at which the tool holding block may be tilted can be measuredby means of a scale scribed on the parts which rotate relative to oneanother. A similar scale may be scribed on portions of the holding blockand the radially extending arm to precisely measure the offset of theholding block on the arm.

In order to measure the are through which the tool is swept as it movesacross the surface of a grinding wheel, a calibrated wheel is attachedto the rotatable shaft and a reference on the stationary portion of thefixture cooperates with the wheel to accurately read the calibrations.lncorporated with the wheel are a pair of adjustable limit stops. Thearc through which the tool is swept can be set by the limit stops inadvance of the grinding operation. In addition, a hand wheel can beattached to the rotatable shaft to facilitate movement of the toolacross the grinding wheel. A shaft lock may be provided if desired tofix the shaft at a given position while the tools or tool supportingstructure are changed or adjusted.

DESCRIPTION OF THE DRAWINGS Referring now to the drawings wherein likeelements are numbered alike in the several figures:

FIG. 1 shows the tool fixture installed in a work environment includingthe positioning of the fixture with respect to a grinding wheel.

FIG. 2 is an elevation view of the grinding fixture with the vise-typetool gripping attachment in place.

FIG. 3 is a plan view of the tool fixture shown in FIG. 2.

FIG. 4 is an elevation view of the milling wheel attachment with amilling wheel partially cut away.

FIG. 5 is a side view of the milling wheel attachment showing the twopositions of the index lock.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference to FIG. 1 shows thegrinding tool fixture generally designated by the numeral 10 installedin a work environment. The fixture 10 supports a tool T in the regionimmediately adjacent to a grinding wheel 12 so that various angular andcontoured tool faces may be formed on the tool T in accordance with thepurposes of my novel fixture design. The fixture is mounted on a movabletable 14 so that it may be positioned with respect to the grinding wheel12. The grinding wheel 12 may be driven by means of an electrical motoror a pulley drive system not shown. The movable table 14 can be attachedby means of bracket 16 to a frame 18 for vertical movement. The verticalmotion of the table permits my fixture to accommodate tools of varioussizes and shapes without requiring the grinding wheel to be moved. For asimilar purpose, mounting platform 20 is horizontally adjustable on thetable 14. By mounting my fixture on the movable table and platform itmay be advantageously employed to support tools of all types and sizes.

Reference to FIGS. 2 and 3 reveals the tool fixture in greater detail.

The main housing 22 of the fixture is mounted to a base plate 24 bymeans of four cap screws 26. The housing 22 forms the principlestationary structural member for supporting the tool from the mountingplatform 20 shown in F IG. 1. A shaft 28 is journaled within the housingby means of bearings 30 at each end wall of the housing. Each end of theshaft 28 extends beyond the bearings 30 in cantilever fashion. Connectedto the one end of the shaft is a hand wheel 32 which may be splined orsuitably secured to the shaft to manually rotate the shaft. A shaftlocking wheel 34 including an internally threaded sleeve or lock nut 36engages the shaft 28 and may be rotated against the end wall of thehousing 22 to lock the shaft 28 to the housing 22. Such a locking wheelmay be desirable to prevent the shaft 28 from rotating while the tool tobe ground or the tool gripping attachments are changed or whileadjustments in the tool supporting structure are being made.

A calibrated dial wheel 38 is secured to the shaft 28 within a slot 40in the housing 22. The wheel 38 extends beyond the upper surface of thehousing 22 and cooperates with a reference pointer 42 mounted on top ofa stop block 44. As an alternate locking device for the shaft 28, aspring loaded plunger 46 may be included within the block 44 and can beaxially displaced to engage a cutout in a nesting block 48 securelymounted to the dial wheel 38. Engagement of the plunger 46 and nestingblock locks the wheel 38 and consequently the shaft 28 to the housing22.

If it is desired to limit the displacement of the tool as it is sweptback and forth across a grinding wheel, two limit blocks 50 may besecured in a circumferential track in the dial wheel 38. The limitblocks 50 can be secured by means of a clamping cap screws (not shown)and will engage the spring loaded plunger 46 to limit the rotation ofthe shaft 28. If no limits are to be placed on the rotation of theshaft, the spring loaded plunger may be latched in a withdrawn positionby a conventional twist lock. If the nesting block 48 is to be securedon the same wheel as the limit block 50 then it is preferable to havetwo positions to which the plunger 46 may be withdrawn. Maximumwithdrawal permits both the nesting block 48 and the limit blocks 50 toclear the plunger and consequently complete freedom of rotation of shaft28 is permitted. At an intermediate position, the plunger is permittedto intercept only the limit blocks 50. When not withdrawn the plungermay fully engage a cutout in the nesting block 48.

At the opposite end of the shaft 28 from the hand wheel 32 a laterallyextending mounting arm 52 is secured to a tapered portion of the shaftby means of a cap screw. Secured to the arm 52 is a radially directedway 54 which dovetails with a slide assembly 56. A pair of cap screws 58may be tightened or loosened to respectively secure or slide theassembly 56 on the way 54. As clearly shown in FIG. 2 a graduated scaleon the arm 52 and a zero index on assembly 56 may be used to positionthe assembly at a preselected offset from the axis of the shaft 28.

The projecting end of the slide assembly 56 includes a curved dovetailedslot. A mating dovetailed portion of a tool attachment adapter 60engages the slot in slide assembly 56 and permits the adapter 60 to berotated in a plane defined by the radially extending arm 52 and shaft28. A cap screw 62 may be used to place the adapter at any desired anglewith respect to the slide assembly 56 and a zero index and scale carriedby the adapter and the assembly may be used to set the angle of theadapter and tool at a preselected value. The ability to tilt the toolwith respect to the axis of shaft 28 is a principle feature of myinvention and permits a tool face to be ground at various angles whilethe tool is simultaneously swept back and forth across the grindingwheel surface by means of the hand wheel 32.

Another feature of my invention is the adjustability of the slideassembly 56 on the laterally extending arm 52. It will be noted that theadjustment permits the tool face to be located either above or below theintersection of the axis of shaft 28 with the grinding wheel. Theangular adjustability of the tool adapter 60 cooperates with the radialadjustability of the slide assembly 56 to permit the angularly of thetool face to be adjusted over a broad range. The radii of the tool facesmay also be adjusted by the radial offset on arm 52.

Another feature of my invention is the capacity of the fixture toaccommodate tools of various types. In one embodiment of the invention avise-type tool gripping attachment 64 is connected to the adapter 60 bymeans of a dovetailed way and cut out as shown in FIGS. 2 and 3. Capscrews 66 may be used to secure the attachment 64 at selected lateralpositions measured by means of the index and the scale carried by theadapter 60 and the attachment 64. The tool gripping attachment 64consists principally of a base member 68, a sliding clamping jaw 70 anda clamping screw 72. As shown in FIGS. 2 and 3 the tool T is clampedbetween the jaw 70 and base member 68 in conventional fashion.

Another embodiment of my invention includes a milling wheel attachment71 as shown in FIGS. 4 and 5. It should be understood that theattachment 71 will be used in place of the vise-type gripping attachment64 shown in FIGS. 2 and 3. The attachment 71 includes way 73 which alsomates with the dovetailed slot in tool adapter 60. Theinterchangeability of the attachment 64 and the attachment 71 ispermitted by identical connectors at the interface with adapter 66).

The miller attachment 71 is composed basically of a mounting plate 74and a milling wheel arbor 76 on which a cutting wheel W or othercylindrical cutters may be mounted. A thumb screw 78 and washer 80 areused to secure the wheel axially on the arbor 76. Arbors of varioussizes may be used to accommodate wheels having different mounting holes.In FIG. 4 the wheel W is partially cut away and the screw 78 and washer80 are removed to clearly show the arbor 76. The wheel W has beenremoved in FIG. for clarity.

To prevent the wheel W from turning while various radii and angles areground on the teeth of the wheel, an index lock 82 is pivotally attachedto the mounting plate 74 by means of a cap screw 84. The lock consistsof a pall 86 and pivot arm 88. A lever 90 extending from the pall 86permits the index lock to be swung from its locked position in which theteeth of the wheel W are engaged by the pall 86 to an unlocked positionshown in phantom in FIG. 5. It will be understood that the screw 78 andwasher 80 could be used to lock the wheel W in position by means of thefriction applied to the wheel from washer 80; however, since the wheelshould not be permitted to shift when it is brought in contact with thegrinding wheel, the more positive index lock is preferred. The plate 74may have a plurality of threaded holes for screw 78 so that wheels ofvarious diameters can be accommodated by the lock 82.

It will be noted that various modifications can be made to the apparatusas disclosed without departing from the spirit and scope of theinvention. For example, while I have shown that the adjustablecomponents can be held in alignment and slide with respect to oneanother by means of dovetailed slots and matching ways, it will bereadily understood that slotted elements with clamping screws spacedalong the slots could be alternately employed. In addition, variouslocking devices such as palls or pins can be employed to hold the shaft28 in position. If desired, the calibrated wheel 38 may be mounteddirectly to the hand wheel 32 and the limit stops 50 could engageabutments projecting from the housing 22 in the path swept by the stops.

Having thus described the various embodiments of my invention I claim:

1. A radius grinding tool fixture for variably positioning a tool duringa grinding process comprising:

a fixture support;

a shaft journaled in the support for rotary motion, said shaft being ona horizontal axis and having a first end projecting along the shaft axisfrom one side of the support in cantilever fashion;

a tool mounting arm secured to the first end of the shaft and extendinggenerally in a radial direction with respect to the axis of thejournaled shaft, said tool mounting arm having a mounting way extendingradially with respect to said shaft axis; and

a tool holder unit slidably mounted to the arm at said mounting way andextending in a horizontal direction, said holder including a toolgripping portion rotatable in a plane defined by said mounting way andthe shaft axis, said tool holder thereby having two degrees of freedomof motion.

2. The fixture ofclaim I wherein:

said tool holder includes a scale and zero index for reading therotational position of the tool gripping portion with respect to thetool holder unit.

3. The fixture of claim I wherein:

the tool gripping portion is additionally adjustable in a directiontransverse to the tool holder unit and the shaft.

4. The fixture of claim I wherein:

the tool gripping portion includes a mounting hub for a wheel-type tooland an indexing lock means for preventing rotation of the tool atpreselected positions of the tool on the hub.

5. The tool fixture of claim 1 further including:

a calibrated wheel mounted to the shaft for rotation therewith; and

reference means mounted to the support and cooperating with thecalibrated wheel for accurately reading the calibrations on the wheel.

6. The tool fixture of claim 5 still further including:

a first limit stop carried by the calibrated wheel on the rotatableshaft;

a second limit stop carried by the support and interposed in the pathswept by the first limit stop for abutment therewith; and

one of the stops having an adjustable position to vary the limit towhich the shaft and the wheel can be rotated.

7. The tool fixture of claim 1 wherein:

the second end of the journaled shaft projects along the shaft axis fromthe side of the support opposite the one side in cantilever fashion; and

a manual rotation member is mounted to the second end of the shaft forrotation therewith.

8. The tool fixture as described in claim I further including:

shaft locking means for securing the journaled shaft and supported toolin a fixed position with respect to the sup port.

1. A radius grinding tool fixture for variably positioning a tool duringa grinding process comprising: a fixture support; a shaft journaled inthe support for rotary motion, said shaft being on a horizontal axis andhaving a first end projecting along the shaft axis from one side of thesupport in cantilever fashion; a tool mounting arm secured to the firstend of the shaft and extending generally in a radial direction withrespect to the axis of the journaled shaft, said tool mounting armhaving a mounting way extending radially with respect to said shaftaxis; and a tool holder unit slidably mounted to the arm at saidmounting way and extending in a horizontal direction, said holderincluding a tool gripping portion rotatable in a plane defined by saidmounting way and the shaft axis, said tool holder thereby having twodegrees of freedom of motion.
 2. The fixture of claim 1 wherein: saidtool holder includes a scale and zero index for reading the rotationalposition of the tool gripping portion with respect to the tool holderunit.
 3. The fixture of claim 1 wherein: the tool gripping portion isadditionally adjustable in a direction transverse to the tool holderunit and the shaft.
 4. The fixture of claim 1 wherein: the tool grippingportion includes a mounting hub for a wheel-type tool and an indexinglock means for preventing rotation of the tool at preselected positionsof the tool on the hub.
 5. The tool fixture of claim 1 furtherincluding: a calibrated wheel mounted to the shaft for rotationtherewith; and reference means mounted to the support and cooperatingwith the calibrated wheel for accurately reading the calibrations on thewheel.
 6. The tool fixture of claim 5 still further including: a firstlimit stop carried by the calibrated wheel on the rotatable shaft; asecond limit stop carried by the support and interposed in the pathswept by the first limit stop for abutment Therewith; and one of thestops having an adjustable position to vary the limit to which the shaftand the wheel can be rotated.
 7. The tool fixture of claim 1 wherein:the second end of the journaled shaft projects along the shaft axis fromthe side of the support opposite the one side in cantilever fashion; anda manual rotation member is mounted to the second end of the shaft forrotation therewith.
 8. The tool fixture as described in claim 1 furtherincluding: shaft locking means for securing the journaled shaft andsupported tool in a fixed position with respect to the support.